THE EFFECT OF PLASMODIUM FLORIDENSE ON RELATIVE LEUKOCYTE COUNTS OF ANOLIS SAGREI AND A. CAROLINENSIS IN FLORIDA, USA

Abstract

Native Green Anoles, Anolis carolinensis, and invasive Brown Anoles, Anolis sagrei, are commonly found in Florida and may be infected with the malarial parasite, Plasmodium floridense. Because no studies have directly addressed health effects of the parasite on Florida anoles, we collected blood smears of infected and uninfected anoles from Central and Southwest Florida and compared the overall leukocyte (WBC) counts, eosinophil counts, and heterophil/lymphocyte ratios. Eosinophils are generally elevated in response to protozoal infection and heterophil/lymphocyte ratios are often altered due to stress. A generalized linear model that tested contributions to erythrocyte/leukocyte ratios included infection status and locality as significant factors. We found significant differences in WBC counts between infected and uninfected lizards in Central Florida but not in Southwest Florida. Central Florida anoles also had higher mean WBC counts than Southwest Florida anoles. We did not detect significant differences in eosinophil counts or H/L ratios related to infection status. Our project is the first to examine leukocyte effects of Plasmodium infection in anoles and to provide leukocyte profiles of Anolis lizards. It appears that infected anoles sustain some negative immunological effects, at least in Central Florida. The differences in regions may be caused by the fact that Central Florida anoles still are under continuous interspecific competition whereas the Southwest Florida Brown Anoles are not because of low populations of Green Anoles. Additional studies that address leukocyte levels related to Plasmodium infection are needed to tease out the health and fitness effects on the lizards of Florida.